1. The Field of the Invention
Embodiments of the present invention extend to methods, systems and computer program products associated with the delivery, tracking, and reconciliation of liquid product inventory. More particularly, embodiments of the present invention provide for a liquid product book inventory to physical inventory reconciliation process that can be initiated and performed on a virtual real-time basis, regardless of ongoing sales transactions. Further, embodiments of the present invention are configured to measure and compensate for temperature variances at every point of physical measurement in order to appropriately reconcile book and physical inventory. In addition, embodiments of the present invention provide for an automated way to request, determine, and monitor the delivery of liquid product to a distribution facility in order to prevent shortages, unauthorized drops, theft, etc.
2. Background and Related Art
Both retail and wholesale liquid product distribution facilities (e.g., gas stations, oil refiners, etc.) are located throughout the nation and other parts of the world. Typically, the liquid product is stored in bulk storage containers or tanks, which may be located above, below, or partially below ground. Each tank may store various petroleum and other liquid products (e.g., gasoline, diesel, kerosene, etc.) to be dispensed through pump dispensers at various retail facilities (e.g., automobile service stations, trucking terminals, automobile rental outlets, and other similar operations). The liquid product is generally delivered to such retail facilities by a gravity drop from a compartment in a wheeled transport such as a fuel delivery truck. These delivery trucks are in turn loaded for delivery from tank systems located at wholesale distribution centers, which may also receive deliveries of product from, e.g., a pipeline spur, delivery trucks, a barge, rail car, or other similar means. The amount of the load is typically reported in a bill-of-lading, which is issued to the retail facility at the time of the drop.
In larger facilities, there may be multiple tanks containing the same or similar liquid product. In fact, tanks containing like or similar product may be manifolded together, allowing them to function as one larger tank. For example more than one tank containing LS #2 Diesel fuel may be plumbed to a common trunk line connecting to multiple fueling dispensers. Additionally, multiple tanks could be plumbed together with a siphon line allowing for the cross flow of product between the tanks. For instance, tanks with premium fuel may be manifolded together with regular fuel tanks, wherein mid-grade fuels are a cross flow of these two types of fuel. For purposes of book inventory to physical inventory reconciliation, the multiple tanks that are plumbed together can be treated as one tank, since it is not always feasible to assign a sales transaction to any one of the tanks individually.
Regardless of the type of tanks, these distribution outlets (both wholesale and retail facilities) are tightly governed by Federal and state laws that require tank systems to have leak detection. One available leak detection processes is known as Statistical Inventory Reconciliation (SIR), which analyzes inventory, delivery, and dispensing data collected over a period of time to determine whether or not a tank system is leaking. Each operating day, the owner of the facility should measure the product level using a gauge stick or other tank level monitor (e.g., an Automatic Tank Gauge (ATG)). The owner is also required to keep complete records of all withdrawals from the tank and all deliveries to the tank. After data has been collected for the period of time required by the SIR, the data may be provided to the SIR vendor or entered into the owners own SIR program. The SIR system then uses sophisticated computer software to conduct a statistical analysis of the data to determine whether or not the tanks may be leaking. The program may then provide the owner with a test report of the analysis results with one of three possible bottom-line responses: pass, fail, or inconclusive.
Although current SIR systems are useful in detecting leaks and are approved by various governmental agencies (e.g., the Environmental Protection Agency EPA), (they also have several shortcomings. For example, in order to use such SIR processes, measurements must take place in a static environment. In particular, no liquid product should be delivered to or dispensed from the tanks during the tank volume measuring process. For small retail facilities that typically have idle times (e.g., during early morning hours), this may not be a big burden. For larger operating facilities that have continual activity (e.g., popular truck fueling stations), however, such required inactivity of the dispensers causes a great burden on the owner and is a big inconvenience for customers who must wait while the measurements are taking place.
Another problem with such SIR systems is they cannot provide real-time monitoring of the delivery of liquid product for accurate inventory. Frequently, there may be overages and shortages in the delivery of the liquid product as opposed to what gets reported in the bill-of-lading. These delivery inconsistencies may be caused by any number of things, for example, inaccurate metering at the rack where the fuel is dispensed into the delivery truck, inconsistencies in the delivery truck's tank not allowing all of the fuel to drop, a bad release valve on the delivery truck, temperature changes from the rack to the tank where it's delivered, and even theft. Regardless of the reason for the inconsistency, as mentioned above because these SIR systems typically require data taken over a large period of time (e.g., a month), they cannot immediately identify overages or shortages in deliveries by taking instant reconciliations before and after a delivery. Nevertheless, even if they could do a real-time reconciliation, because they cannot operate in a dynamic environment, they cannot give on-demand reconciliation when pumps are active. Accordingly, in order to use SIR for determining delivery shortages, deliveries would need to be made during idle times, which could be difficult, if not impossible, to schedule.
A related problem with current SIR systems is that, because they cannot do real-time monitoring of the change in volume within a tank, they cannot immediately determine if liquid product is being dropped into an unauthorized tank or if the level of water within the tank is too high. An unauthorized drop, however, can have serious consequences. For example, if the wrong petroleum product is unknowingly dropped into an improper tank, extreme damage may occur to vehicles fueled with the improper product. In addition, during a drop, the sediment at the bottom of the tank may be disturbed causing the level of water within the tank to rise dramatically. Such a rise in water volume, however, can also be siphoned into the dispensing system, causing those vehicles fueling during the surge to get water instead of fuel.
One solution to such problems would be to manually monitor the drop through, e.g., an ATG. This rudimentary solution, however, has several downfalls. For example, often times a drop cannot be anticipated; and therefore one might not even know when an unauthorized drop has occurred. In addition, by the time it is determined that the unauthorized drop is occurring or that the level of water in the tank is rising to dangerous levels, it may take several minutes to run out and stop the unauthorized or dangerous drop, while the damage has already occurred.
Another problem with SIR reports is that they don't take into account temperature differences at every physical point in the distribution process. When the liquid product is initially loaded into the delivery vehicle, it is at a first temperature that can be reported in the bill-of-lading. Depending on a myriad of factors, however, the temperature of the liquid product can change dramatically during the distribution process. For example, the temperature of the liquid product may change depending on the temperature difference where the delivery truck was loaded and where the drop was made, the time of day, whether the tank is above or below ground, etc. These temperature differences, however, can have an enormous effect of the measured volume of the liquid product and can be the cause of error in the SIR system.